premature ventricular beats, the most common of all arrhythmias; in the absence of heart disease, they are not of great clinical significance, but in patients with coronary disease, they represent a constant danger of ventricular tachycardia or fibrillation and sudden death.

Definition (MSH)

A type of cardiac arrhythmia with premature contractions of the HEART VENTRICLES. It is characterized by the premature QRS complex on ECG that is of abnormal shape and great duration (generally >129 msec). It is the most common form of all cardiac arrhythmias. Premature ventricular complexes have no clinical significance except in concurrence with heart diseases.